Will this work (vfd)

balibalistic

balibalistic

Joined
Jul 14, 2004
Messages
2,623
Hey guys,

would this little set up be worthwhile to make a small variable sharpening grinder.

The guy says its AC and motor is 56 frame tefc. but the controller clearly says DC. i assume that the gear could be removed to use as just the motor/controller? also said the controller is nema 4 but i have my doubts.
just curious if its worthwhile? what do you's think? appreciate any input.

http://www.hermanstools.com/view-listing.php?id=2162
 
"Will this work?"

Not for a grinder.
aim for a 3400 rpm motor
aim for Minimum 1 hp

The controller is clearly DC,
a DC controller needs a DC motor

I get the impression that the wires are just tangled together to seem like it is a package rather than 2 separate things thrown together. Why wouldn't he post pics of that motor specs plate already ?


Ask for a photo of the data plate on the motor.
HP, phase, rpm, voltage

That square box is a gear reduction drive. turning your 1700 rpm to 175 rpm
If you are thinking grinder, you need to take that gear reduction off.


How much for that ?
It could be a good deal for a dc controller box, but if you want to run a grinder with that controller, you need to to find a relatively rare and expensive DC motor(assuming that is an AC motor)

That controller looks NEMA 1 to me
 
Last edited:
Thanks man. i do own several 2x72" belt grinders and i am running both AC and DC set-up's. i guess my main concern is, can i get the gear reducer off and what might this be worth? i dont plan to use it on an actual grinder but rather a small knife sharpener that i built, i'd like to rebuild it with variable speed.

DSC00908.jpg
 
balibalistic said:
Thanks man. i do own several 2x72" belt grinders and i am running both AC and DC set-up's.

i guess my main concern is, can i get the gear reducer off and what might this be worth?

i dont plan to use it on an actual grinder but rather a small knife sharpener that i built, i'd like to rebuild it with variable speed.
Click to expand...

In that case, 1/2 hp and 1700 rpm is fine for this sharpener..

I say yes you can get that reduction drive off that motor, remove the 4 screws you see on the end of the motor.

Prices of reduction drive are dependant on their HP rating and gear reduction ratio. from a couple of hundred up

...but again, I don't see that DC drive working with that AC motor...
that AC motor needs a VFD

OR

Just change that design to use the 175 rpm output of that gear drive and forget that variable speed, just use low speed
 
So is the motor/controller worth $300? i think he made an error saying it was AC. i believe it is functioning.
 
balibalistic said:
So is the motor/controller worth $300? i think he made an error saying it was AC. i believe it is functioning.
Click to expand...

How would you know, maybe that is just wishful thinking?

I think you can find better deals than that.

I would wait for a photo of that motor data plate.

Why would you buy from a Canadian seller rather than in USA ?
You are going to pay a lot more in shipping


I recently used e bay for the first time and found a 3 phase 1.5 hp motor for 50 + 50 shipping.
I would tend to hold out and buy exactly what you want, unless that package was much cheaper and you already had a use for that gear reducer drive.
 
Last edited:
I just received a photo of the motor it is DC

Leeson
DC 90V 1700 rpm

That makes it a reasonable deal in my opinion.
 
If this is the best deal you can find on a DC motor, then yes. I am running my sharpener with a small DC motor and the power sypply is a VARAC. A varable transformer tied into a bridge rectifier. I use the rectifer for the sharpener, DC buffer, and to anodize. You can find them on Ebay most of the time for $60 +/- I have been using this for many years with good results.

Paul
 
It looks like a DC motor and Controller to me. I have a 1hp 1750 rpm DC on one of my disc grinders and it works just fine. I do like my 1.5hp 3ph with the VFD much better. and $300 is a lot for what he is selling. If you look hard enough you could get a really good 3ph motor and VFD for much less than that. I got 2 washdown rated motors, 1hp and 1.5hp 1500 and 3500 rpm delivered for less than $100. You can find the VFD's for around the same if you wait long enough.
 
Thanks guy's. i knew it was'nt a steal. just would work well with what i have in mind. two weeks ago i scored a 1hp boston gear DC motor/controller for $150. controller is nema 4 and makes my KB look like a pocket control :) works like a champ, though. that was a good deal.
 
Question guy's, i ended up grabbing this as it was just down the street and i got a great deal. it's virtually all brand new. it has two cut off cords, plugs i assumed. i wired the one that had tape on it saying main power, plugged it in and everything works great, forward/reverse and break switch. what the heck is the other cord for???

i am an electrical fool..., if ya cant tell :)
 
Just over $200. i could probably sell the grove gear reducer and make double my money back.

Now for the cord, could this have been to a remote of some sort? it clearly does not need anymore power to it so thats all i can think.
 
I just tore it apart, removed the cord which was wired in with the forward/reverse box and were good to go. another question:

The controller is nema 1 enclosure. could i mount it under the lip of my bench which will fully cover it from above, and just blow it off when i clean the shop a couple times a week? or should i build a protective box for it. i see they sell nema 4 enclosures on e-bay, too.
 
the other cord was probably for a pendant controller. If you can get a nema 4 it would be better but what I wound up doing was taping up all the seams on one I have and it works great, but I still would recommend the nema 4.
 
The fuse is swappable, and there are real good manuals for the KB controls out there.

You probably have basically the same control, in a different case...
 
Well i got the entire manual/warantee. i opened up both controls and they are nothing alike. i read the manual and it's in chinese..., ok, maybe not but it may as well be. the unit i'm running now has a searate box to farward/reverse so that is messing me up to. oh goody, this will be fun.:jerkit:
 
Edit : I glitched, and looked at the wrong info...
Sorry

New Manual

Old Manual

Your new controller is real easy to hook up.
2 AC lines and a ground in.
2 Wires out to the motor.

The remote box on the old one can be handy, but isn't necessary.
I'm fixing to build one next week for a horizontal I'm making.
 
Last edited:
You must log in or register to reply here.
Back
Top